This invention relates generally to miniature electrical circuit connectors and more particularly to miniature DIN connectors or receptacles, so called "mini DIN's", and specifically to means for effective electrical grounding of such connectors.
ECB miniature DIN connectors are well known in the art and are exemplified in U.S. Pat. Nos. 4,842,554; 4,842,555; 4,925,405; 4,493,525; 4,925,405; 4,913,664; and 4,637,669. These connectors are standard electrical plug compatible connectors used by manufacturers to provide for connection of electrical equipment, such as, computers, audio or video equipment, to one another and to peripheral components. One basic utility today for such connectors is connection of mouse cursor devices to computers. The conventional mini DIN connector is circuit board mountable and includes terminals with solder tails or surface mountable contacts for making appropriate electrical connections to conductive receiving portions of a circuit board.
Further, government agencies and authorities require strict compliance to EMI standards to ensure that electromagnetic energy is maintained to an approved level. The conventional manner of controlling EMI is the use of a metal member that covers and surrounds the connector terminals mounted within the plastic body of the mini DIN connector and is grounded to the circuit board on which the connector is mounted. The forward end of the connector containing the plug receptacle is exposed through an aperture provided in the grounding shield. These shields are designed to suppress undesired levels of EMI generated from electrical components in the immediate region of the mounted mini DIN connector.
Many types of electrical equipment which employ mini DIN connectors mounted along the rear edge of a horizontally mounted circuit board in a chassis, such as a main circuit or mother board of a computer or other such equipment. Openings are provided in a rear vertical panel or backplane of the equipment for receiving an external plug in the connector receptacle through an aperture in the backplane. The backplane also function as ground planes that also aid in the suppression of EMI. Thus, it is desirable to electrically ground the backplane to the EMI shield of the mini DIN connector. This, however, is not an easy task since the mini DIN connectors are mounted on the mother board and the vertical backplane is a separate component and assembled into the equipment differently and separately from the mother board. This makes it difficult to ground the mini DIN connector shield to the backplane as there is a multitude of tolerance differences from chassis to chassis. The issue is, then, how can this electrical ground connection between the mini DIN ground and the backplane be accomplished in a simple assembled and maintained manner.
One manner employed in making this electrical secured contact between the mini DIN connector and the backplane is the use of a mechanical connection in the form of a sheet metal screw for securing the mini DIN EMI shield through an extension thereof directly to the surface of the backplane. Not only does this require extra parts but also is an additional task to complete the necessary connection of one or more mini DIN type connectors to the backplane after these latter components have been assembled and soldered into the main circuit board. Further, disassembly for repair or maintenance is hampered by the necessity of, first, disconnecting the main circuit board mini DIN connectors from the backplane before removal of the main circuit board can be removed from the equipment chassis.
Furthermore, the standard mini DIN connector design utilized today can not withstand subjection to a solder bath with the component mounted circuit board because they are not flow solderable and the electrical terminals provided in the apertures of the connector are easily contaminated by solder flux thereby affecting good connectability.
It is an object of the present invention to provide a means for achieving and maintaining sustained electrical contact between a mini DIN connector ground shield and a ground backplane without the need for a fastened or mechanical connection.
It is another object of this invention to provide a mini DIN structure that can be subjected to a solder bath, as connected to a circuit board without contamination of the mini DIN socket or receptacle from exposure to solder flux.